010 - Library of Congress Control Number (NR)

$z - Canceled/invalid LC control number (R) $8 - Field link and sequence number (R)

FIELD DEFINITION AND SCOPE

Unique number assigned to a MARC record by the Library of Congress. Valid MARC prefixes
for LC control numbers are published in MARC 21 Format for Bibliographic
Data.

The control number for MARC records distributed by LC is an LC control number (LCCN).
The LC control number is carried in field 001 (Control Number) in records distributed by
LC's Cataloging Distribution Service and in field 010$a. An organization using LC
records may remove the LC control number from field 001 and use field 001 for its own
system control number.

An LC record may contain field 010 with a canceled or invalid control number of a
previously-distributed record. A record may be canceled because it is a duplicate record
for the same item. The structure of the canceled/invalid control number is the same as
that used by LC in field 001.

GUIDELINES FOR APPLYING CONTENT DESIGNATORS

■ INDICATORS

Both indicator positions are undefined; each contains a blank (#).

■ SUBFIELD CODES

$a - LC control number

Valid LC control number (see explanation of structure of this number given
below).

010

##$a###85153773#

010

##$anuc76039265#

010

##$a##2001627090

010

##$a##2001336783

$b - NUCMC control number

Valid entry number for the item being described as found in National Union
Catalog of Manuscript Collections (NUCMC). The number begins with the
prefix ms.

010

##$a###89798632#$bms#89001579#

$z - Canceled/invalid LC control number

Canceled or invalid LC control number, including invalid NUCMC numbers.

INPUT CONVENTIONS

Classes of LCCNs - LCCNs may be valid, canceled, or invalid (structurally or application) for the record.
The following conventions are followed to select the appropriate subfield for an
LCCN.

Valid LCCN: - A valid LCCN for a record is the one that appears in the 001 when the record is
distributed by LC. It has correct length and structure.

Canceled LCCN: - A record, hence its LCCN, may be canceled for a variety of reasons, very often because
it is a duplicate record for the same manifestation of a resource. An LCCN is considered
to be canceled when LC designates it as such.

Structurally invalid LCCN: - An LCCN is considered structurally invalid when its length or structure is incorrect
according to the practices of the Library of Congress.

Application invalid LCCN: - An LCCN is invalid in application when it appears on the item being cataloged but it is
not the LCCN of the record for the item, e.g. the LCCN assigned to the record for one
edition is also printed in another, different edition which has its own record and
LCCN.

Punctuation - Field 010 does not end in a mark of punctuation. A slash is used to separate revision
information from the control number and any suffix. Multiple suffixes are also separated
by a slash.

Capitalization - Prefixes are always input as lowercase alphabetic characters. Suffixes and alphabetic
identifiers added to the end of the LC control number are input as uppercase alphabetic
characters.

STRUCTURE OF THE LC CONTROL NUMBER

The LC control numbering system has had the same basic structure since its initial use
to control Library of Congress bibliographic information in card form beginning in 1898
(LCCN structure A). On January 1, 2001, a structural change occurred (LCCN structure B).
The basic control number has been fixed in length at 12 characters and will remain that
length, although under LCCN structure A suffixes were occasionally used and under LCCN
structure B the location of element parts is slightly altered to accommodate a four
digit year. Under both structures, the prefix, year, and serial number are the basic
elements required to make an LCCN unique.

LCCN Structure A (1898-2000)

Name of Element

Number of characters

Character position in field

Alphabetic prefix

3

00-02

Year

2

03-04

Serial number

6

05-10

Supplement number

1

11

Suffix and/or Revision Date

variable

12-n

LCCN Structure B (2001- )

Name of Element

Number of characters

Character position in field

Alphabetic prefix

2

00-01

Year

4

02-05

Serial number

6

06-11

Alphabetic prefix

Prefixes are carried in a MARC record as lowercase alphabetic characters and serve to
differentiate between different series of LC control numbers. Prefixes are left
justified and unused positions contain blanks. If no prefix is present, the prefix
portion contains blanks.

010

##$a###68004897#[LCCN structure A; number on printed card: 68-4897]

010

##$a##2001045944[LCCN structure B; number in print form: 2001-45944]

Prior to the existence of MARC records, prefixes of various lengths were used on printed
cards with combinations of uppercase or lowercase letters and numbers. For MARC records,
equivalents have been defined by the Library of Congress for some of these early
prefixes, including those that were longer than two or three characters. All other
prefixes are input as found but in lowercase. The first column in the list below gives
prefixes found on printed cards not printed from machine-readable records and shows how
they are to be input into a MARC version of the record. The list also includes some MARC
prefixes not found only on MARC records. Only prefixes which have a MARC form noted
below should be recorded in machine-readable records. (The alphabetic prefix for the
Library of Congress control number is an authoritative-agency data element, maintained
by the Library of Congress.)

Since the prefixes were used in records before 2001, they are found in the LCCN
Structure A only.

LCCN Prefix Table

Note: In the first column, an asterisked (*) item indicates the form in which the prefix
appears on the card.

Prefix on card

MARC Prefix

Explanation of usage

A

a

Cataloging provided to LC by an American library, 1909-

AC

ac

Cataloging for foreign materials provided to LC by cooperating libraries under
the auspices of the ALA Committee on Cooperative Cataloging, 1932-1942

AC

ac

Annotated cards for juvenile books, 1966-

AF

af

Cataloging for foreign acquisitions provided to LC by other American
libraries, 1946-1950

For control numbers assigned under LCCN structure A, the year portion consists of two
digits normally representing the year the record was created. For control numbers
assigned under LCCN structure B beginning with the year 2001, the year portion consists
of four digits.

In most numbers, the year portion reflects the year in which the LC control number was
assigned to the record for the bibliographic item. During the 1969-1972 period, a
7-series year number was assigned. In these numbers the initial digit of
7 was followed by a modulus-ll check digit. The year in which the card
number was assigned can be approximated from the year portion of the Date entered on
file (008/00-05). With the re-institution of the year series number in 1972, provisions
were made to skip those individual card numbers which could have been assigned
previously as a 7-series number. Note: 7-series numbers were not used for
non-book map material. The prefix gm was used from 1968 through 1972.

For LC control numbers with two-digit years, the century may be determined according to
the following table:

2-digit year

Sequential number

Century

Sequential number

Century

98

Less than 3000

18

3000 or greater

19

99

Less than 6000

18

6000 or greater

19

00

Less than 8000

19

8000 or greater

20

Serial number

Serial number portion consists of one to six digits. Serial numbers of less than six
digits are right justified and unused positions contain zeros. The hyphen which
separates the year and the serial number on LC printed products is not carried in the
MARC record. For example, the number 85-2 is carried as 85000002 in a record.

Supplement number (LCCN structure A only)

This character position was originally defined to carry a supplement number for
dashed-on supplement entries in bibliographic records. Use of the supplement number was
not implemented, therefore this position contains a blank. Supplements and similar
materials are now cataloged separately by LC and are carried as separate records with
their own LC control number. In some older records, information about supplements and
similar materials is given in a 500 note field.

Suffix/Alphabetic Identifier (LCCN structure A only)

Older LC control numbers sometimes include suffixes or alphabetic identifiers carried as
variable length data following the Supplement number. A single slash (/) introduces the
suffix/alphabetic identifier. Multiple occurrences of either suffixes or alphabetic
identifiers are separated one from the other by a slash. Suffixes and alphabetic
identifiers do not affect the uniqueness of the control number.

All suffixes and alphabetic identifiers, except the revision date, appear in the MARC
record as uppercase alphabetic characters. On printed card copy, suffixes appear after
the LC control number separated by a slash. Suffixes have not been assigned since 1969
and they will be deleted from Library of Congress files in 1999. Alphabetic identifiers
appear on printed card copy as uppercase alphabetic characters beneath the LC card
number in the lower right hand corner of the card. Alphabetic identifiers were first
assigned in 1969 and were used as distribution information for card copy by LC.
Alphabetic identifiers will be deleted from the Library of Congress files in 1999.

010

##$a###79139101#/AC/MN[Printed number is 79-139101 with AC MN printed below the number.]

010

##$a###65077628#/MN[Printed number is 65-77628 with MN printed below the number.]

Suffix/alphabetic identifiers

AC

used on records included in the "Annotated Card" program

AM

used for works in Amharic

ACN

used for works in Chinese

AJ

used for works in Japanese

AK

used for works in Korean

F

used for records created by the Audiovisual Section, Special Materials
Cataloging Division for motion pictures, filmstrips, sets of slides and
transparencies, video recordings, etc.

HE

used for works published in the Hebrew alphabet, regardless of
language

M

used for works classed in M

MAP

used for atlases

MN

used for works classed in ML and MT

MP

used for records created by the Motion Picture, Broadcasting and
Recorded Sound Division

NE

used for works in Armenian, Arabic, Georgian, Ottoman Turkish, Persian,
Pashto, and Turkish, as well as any non-Slavic language of Central Asia
written in the Cyrillic alphabet

PP

used for records created by the Prints and Photographs Division

R

used for all sound recordings

Revision Date (LCCN structure A only)

Revision dates associated with LC control numbers specify the latest date that the
bibliographic data in a record underwent a change. Revision data do not affect the
uniqueness of the control number. To account for the number of times significant changes
have been made to a record beyond the first such change, a number was added as the last
character of the revision date. The date a record was originally created is the Date
entered on file (field 008/00-05).

A revision date such as “r73" means that the record was changed in 1973. The
revision date “r743" means that significant changes have been made to the
record three times, the last being made in 1974.

##$a###58062665#/L/r58[Printed number is 58-62665 rev*. (The * was represented on the printed product
by a double dagger and indicated limited cataloging; it was carried in the MARC
record as an L. When the LC control number was printed from the MARC record, the L
printed as Lim beneath the control number.)]

Revision date was used as an indication of the degree of importance of a change made to
a record. A significant change to a record at the Library of Congress was defined as one
important enough to warrant, among other things, redistribution of cards to LC's own
catalogs. A significant change included changes to content designation, to an access
point (fields 020, $a or $z, 028, $a, 050, 051, 082, 1XX, 240, 245$a, 4XX (excluding
490), 6XX, 7XX, 8XX), a change to the extent of an item (300$a), a change to the
publication date (260$c), a change to the record control number (field 001), or a change
to Leader/18 (Descriptive cataloging form).

Revision information was separated from a suffix or an alphabetic identifier by one
slash (/). If no suffixes or alphabetic identifiers are present, revision information
was separated from the Supplement number by two slashes (//). The inclusion of revision
data was discontinued in 1999 and will be deleted from all records in the Library of
Congress files.